Indian Railways is changing the train number of all the Express and Mail trains. From Dec 20, the new train number will be five digit than the four digit number. It is easy to remember this change, just add 1 to the existing train number. If the train number is 2657 then the new number will 12657. Please note this change as you make reservations for train travel after Dec 20,2010. Soon they will change the passenger train numbers as well from three digit to five digit numbers.